Fluid-pressure engine.



No. 636,926. li atented Nov. |4, |a99..

. 'SEBPOL'LET. v

FLUID PRESSURE ENGINE.

(Application filed Nov. 18, 1898.)

'(No Model.)

I sgiw W,

UNITED STATES- PATENT OFFICE.

LEON SERPOLLET, or PARIS, FRANCE, Asst anon TO LA sooinrn DES enNERATEURs A VAPORISATION INSTANTANFE, sYs'rEME LEON SERPOLLET,) OF FRANCE.

FLUID-PRESSURE ENGINE;

SPECIFICATION forming part of Letters Patent No. 636,926, dated November 14, 1899. Application filed November 18, 1898- Serial No. 696,801- (No model.)

T0 at whom it may concern:

Beit known that I, LEON SERPOLLET, of the city of Paris, in the Republic of France, have invented. a new and useful Improvement in Fluid-Pressure Engines, which is fully set forth in the following specification.

This invention relates to improvements in steam-engines, and has for its object to construct engines which are adapted for the purpose of utilizing more particularly steam superheated to a very high temperature, which may rise up to 400 and even 500 centigrade, such engine being also suitable for working with compressed air or other permanent fluid. Engines according to this invention are provided with valve gear of great simplicity, comprising a central cam of special form and operation; and further objects are to dispense with packings of piston-rods and of the slide -'valves and also with the surfaces on which the said slide-valves work, to effect an abundant lubrication without the aid of the usual lubricators, and, finally, to provide successively a free exhaust without the aid of a slide-valve, while at the same time effecting compression of the remainder of the fluid imprisoned in the cylinder on the return stroke of the piston. The engine to which these means are applied and which shall now be described is of a known type and comprises a group of two or more horizontal or vertical cylinders arranged opposite to. one another or side by side or radiating, the said cylinders being single-acting and opening into a common chamber in which a simple drop-feed lubricator maintains a constant level. Through this chamber passes the engine-shaft, and in it there moves the common crank, which just dips into the oil contained therein and to the crank-pin of which are attached the heads of each of the engine connecting-rods situated in the same plane. These connecting rods are each jointed directly to the bottom of a hollow piston which works in a correspondingcylinder. In adjacent parallel planes there may be arranged groups of two, three, or more cylinders arranged opposite to one another, and these groups may be connected or coupled to crank-pins arranged tandemwise or at right angles, or, if there are three groups, at one hundred and twenty degrees, each group con sisting of two or more cylinders situated in different parallel planes. I I

In the accompanying drawings, Figure lis a half side elevation and half longitudinal section of an engine having two cylinders arvalve-gear arranged on the end of the engine shaft in the case of an engine having four cylinders arranged vertically side by side with the cranks at the bottom.

The two single-acting cylinders a. a, Figs. 1 to 6, are mounted in line with and facing each other on the frame I), having the general form of a cylindrical box. The pistons are recessed and have a considerable length relatively to their diameter, which allows of jointing the connecting-rods directly thereto and dispensing with the piston-rod, its stuffing-box, and the slides. The two connecting-rods have their heads cut away somewhat in the form of a crescent in such a manner as to be capable of being both supported in one and the same plane of rotation by means of a common crank-pin c. As they only Work in compression the cap of the end bearing is superfluous. However, for the purpose of avoiding any possible derangement there are provided two collars d, which embrace the shoulders of the heads of the connecting-rods and keep them constantly up against the crank-pin.

The steam enters the cylinders through the outer end of each of said cylinders on the opening of the corresponding valve 6, which is operated by means of mechanism hereinafter described. when each piston has arrived at the end of its power-stroke, it uncovers the-orifices f or the orifices f, Fig. 7,

of which the first are formed in the wall of the cylinder, while the latter are formed in the walls of the central tube T, through which the fluid exhausts. However, the cylinder remains full of the expanded fluid (steam or air) at a pressure which may be slightly above that of the atmosphere and which may besides depend on various causes, such as counter-pressure of exhaust, very short duration of the exhaust period, (X56. This steam being imprisoned on the return stroke of the piston is compressed up to the end of the stroke without having to fear, as would be the case in all slide-valve en gines,that the compression will exceed the pressure in the boiler. In fact, as soon as the compression in the cylinders exceeds the pressure in the generator, although the valve 6 is pulled by the tension of the spring the said valve 6 will open and allow the compressed steam to return into the supply-pipe, whence it will return afterward into the cylinder at the commencement of the next power-stroke. It will be readily understood that this faculty of limiting the pressure in the cylinder to an extent practically equal to the pressure existing in the boiler will allow of practically doing away with the dead-spaces, and will thus effect a considerable saving in steam or air.

The distributing-gear employed in this engine is of special construction and is of the valve type, and the valve mechanism is situated on or against the framing. The mechanism comprises a small shaft g, parallel to the engine-shaft and rotated by the latter by means of a pair of toothed wheels h h. This small shaft'carries a cylindrical cam 7', which is adapted to slide along a feather and is thus capable of moving longitudinally when it is actuated by the nut i, which is provided with a forked tail embracing the circular groove formed in the end of the cam. This nut is mounted on a screw 4;, parallel to the axis of the said cam, and moves when the said screw, which is held between two stops, is turned either by hand or by a governor. In its rotary movement the cam j moves successively, by means of one of its two noses or projections, the rollers Z, mounted on the ends of the sliding rods k, and the end of which serves as a cap or housing forthe axle of these rollers. By these means the cam raises the admission-valves c, which are normally pulled by opposing springs in such a manner that these valves have a tendency to remain on their seats, both by reason of the tension of their springs and also by the'pressure of the steam.

If the engine which has just been described is intended to rotate in one direction only with a constant admission of steam, the cam would then only have to be made of the total width of the two rollers, with an incline or projection whose length would correspond to the fixed period of admission which was determined upon; but in order that the engine should be capable of being reversed and have a variable cut-0E, either by hand or by the governor, the cam j is provided with two projections or inclines s 5, arranged symmetrically opposite to each other in the same plane and each having the form somewhat of a right-angled triangle. The apex of each of these triangles ends a few millimeters distance from the central plane, which is at right angles to the axis of the cam, and it terminates in the cylindrical surface of the said cam. These two triangles are thus opposed one to the other at their apices,which are separated by a space equal to the thickness of one roller and correspondin g to the period or position of stoppage. They each have a side situated upon one and the same generating-line and developed one to the right and the other to the left. (See Fig. 4.) The consequence is that, according to the position of the cam j upon its longitudinal axis and opposite to the rollers l, one on each side of the cam, the said rollers are raised or pushed back during the tangential travel of the said cam, which is greater or less-that is to say, during a shorter or longer periodaccording as these rollers pass over the apex of the projecting triangles on the opposite side, which is most prominent toward the outside, or over an intermediate circle situated between these two limits, so that the admission can vary from zero (when the rollers are situated in the middle plane between the apices of the triangles) up to the maximum degree when they are situated quite close to the outer faces of the cam. Between these limits there may be obtained an indefinite number of intermediate points and degrees of cut-off or admission. In order to change the direction of motion, it is sufficient to move the cam j forward on its axis in such a manner as to change the position (relatively to the rollers) of the triangular nose or projection of that cam which actuates the said rollers, as above described.

It will be seen that the operation of the cam j allows of producing forward running of the engine with any desired admission of steam, of stopping the engine, and of producing backward running with any desired degree of admission.

The operation of the screw actuating the cam j may be efiected either by hand or by means of a governor actuating it in any desired manner-401' example, as indicated in dotted lines in the drawings.

The lubrication of the cylinders, the heads of the connecting-rods, and the bearings of the engine-shaft is effected in a very simple manner by means of a drop-feed lubricator, which drops oil into the lower part of the chamber into which the crank dips, and thereby at each revolution throws the lubricant in all directions by its motion, and thus insures a very copious lubrication of the pistons and working parts.

The engine hereinabove described is characterized by the absence of stufling-boxes, slides, and slide-valves for the admission,

which may vary between 'very wide limits, as

well as for the exhaust, the'admission and exhaust being efiected, the former by means of a readily-accessible valve actuated by a cam having a variable throw, the latter (the exhaust) by means of simple orifices f, which are formed at a suitable point in the wall of the cylinder and to which there is connected an exhaust-pipe, the said orifices being opened or shut at a desired moment by the piston itself. I r

It will be noted that the admission is effected in succession in each of the cylinders situated in one and the same plane by means of one and the same cam, whose incline or projection (either the one for forward travel or the one for backward travel, which is situated symmetrically opposite thereto.) moves 3 (at each half-revolution, if the engine has two opposite cylinders, or at each third of arevolution, if the engine has three rotating cylinders situated'in one and the same plane) in front of the roller which operates the rod of the corresponding admission-valve.

When the cylinders are arranged two or three in one and the same plane and two or three in another adjacent and parallel plane, each separate group of two or three cylinders situated in one and the same plane has its valves, its distributing-cam, and all the parts or mechanism hereinabove described.

As already stated, the cylinders may be arranged vertically and side by side irrespective of .the number of the cylinders. The frame serves to support the cylinders and to protect the moving part arranged underneath.

In the case ofa motor consisting of four cylinders arranged vertically side by side each of the cylinders carries its distributing-valve operated by its own cam.

There are thus as many cams as thereare valves, each cam producing forward and rearward running. A single cam J may, however, suffice to eifect distribution for any desired number of cylinders arranged vertically side by side and situated in one and the same plane with a chamber to contain the moving parts underneath if the said cam is situated on the outside of the engine-shaft, as shown in the end view, Fig. 8. In this manner the motion of the cam is effected without the aid ofanintermediateshaftand gear. Thevalves are placed around the engine-shaft in such a manner that their respective angular positions correspond to the angular positions of the cylinders controlled thereby. They are connected together by means of a steam-supply passage cast in one with the bodies of the valves and serving as a casing for the latter. The steam-passages, which connect the valvechambers with their respective cylinders,

serve as compression-spaces, and for this reason they must all have the same capacity. Having now particularly described and ascertained the nature of the said invention and in what manner the same is to be performed, I declare that what I claim is-- 1. In a steam-engine, a plurality of singleacting cylinders having inlet and exhaust ports and opening at their inner ends into a common chamber, a driving-shaft Working in said chamber, pistons in the cylinders, and pitmen connecting said pistons with the driving-shaft, valves controlling the steam-- inlet ports, a rotatable cam-surface of tapering width, valve-rods for the valves projecting toward and terminating at opposite sides of and adapted to be successively acted upon ,a'cting cylinders having inlet and exhaust ports and opening at their inner end into a common chamber, a driving-shaft working in said chamber, pistons in the cylinders, and pitmen connecting said pistons with the driving-shaft, valves controlling the steam inlet ports, a rotatable cam comprising a sleeve having thereon two acting cam-surfaces tapering from their point of greatest width inwardly toward the middle of the sleeve, but separated at their inner ends by a non-acting space, valve-stems for the valves projecting toward and terminating at opposite sides of the cam and adapted to be acted upon in succession by the cam-surfaces respectively to open the inlet-valves, means for moving said cam laterally with reference to the valve-stems, and gearing for continuously rotating said-cam while the engine is run ning.

3. In a steam-engine, a plurality of singleacting cylinders opening at one end into a common chamber, pistons in said cylinders, a driving-shaft Working in said chamber, pitmen connecting the pistons with said driving-shaft, exhaust-ports for the cylinders adapted to be opened or closed by the movements of the pistons themselves, inlet-ports forithe cylinders, outwardly-opening puppetvalves controlling said inlet-ports, stems for said valves, springs acting on said stems to hold the valves normally closed, and means acting on the valve-stems at proper intervals, for opening the valves against the tension of the springs.

4. In a steam-engine, a plurality of singleacting cylinders opening at one end into a common chamber, pistons in said cylinders, a driving-shaft working in said chamber, pitmen connecting the pistons with said driving-shaft, exhaust ports for the cylinders adapted to be opened or closed by the movement of the pistons themselves, inlet-ports for the cylinder, outwardly-opening puppetvalves controlling. said inlet-ports, stems for said valves, springs acting on said stems to hold the valves normally closed, a rotatable to bring either of the cams or a wider or narrower part thereof, or the non-acting intermediate space thereof, into alinement with said stems.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

LEON SERP'OLLET; Witnesses:

EDWARD BEUGNIOT, J. ALLISON BOWEN. 

